Cinderella, with an accordion

Five years ago in Paris, Brook directed Rossini’s opera “La Cenerentola,’’ which offers a different version of the tale, one with less fairy tale magic and more old-school plot devices, such as the prince masquerading as a servant. Initially resistant, Brook slowly fell in love with it.

“I was very curious to know if it would be transferable to the theater,’’ she says. “Part of the appeal of the opera is, of course, the music, the main part of it. And yet I did feel that the story was so delightful and universal and thrilling.’’

Thus we have “Cindy Bella (or The Glass Slipper),’’ an offbeat world-premiere adaptation by Brook and Anna Brownsted, running through Dec. 20 at Shakespeare & Company in Lenox. The new play is built on the chassis of the opera, taking musical and other cues from Rossini.

In the opera, “There’s no pumpkin, there’s no carriage and no mice, and there’s not even, extraordinarily - I have to say I felt pretty ripped off - there’s not even a glass slipper or a shoe of any sort,’’ Brook says. “There’s a couple of bracelets. She hands him a bracelet at the ball as she runs off, and says, ‘If you can find the girl with the second bracelet, I will be yours.’ But it’s true when you’ve been brought up on a nice line of shoes, it’s very different to let go of that, so we’ve returned to the old shoe.’’

Brook, director in residence at Shakespeare & Company and the daughter of Peter Brook, the renowned British director, has set “Cindy Bella’’ in a strange world of her own making.

“It’s my favorite theatrical world, a sort of nonspecific, retro no-man’s-land of the ’50s, ’60s, ’70s, ’40s. It’s got a certain nostalgia feel, the old crumbling Hollywood-music-hall feel of yesterday,’’ Brook says. At the same time, “it’s absolutely contemporary, everything in the behavior and language is of today. . . . What we’ve got here is quite a crazy mix.’’

In this version, Cindy Bella is a streetwise accordionist, which happens to be the instrument played by Heather Fisch. The actress first played the role in a work-in-progress presented last winter. Brook created the show with her in mind.

“It all seems like a pretty natural fit somehow, which seems totally absurd,’’ Fisch says with a laugh, “because there are a bunch of different genres that don’t really seem to have much of a connection. She’s somehow weaved them together to make a cohesive style, which is impressive.’’

“Irina has a great talent for being able to integrate almost anything that takes her fancy into the production and somehow make it work,’’ says Scott Renzoni, who plays Don Ramiro, a.k.a. the prince.

But wait, there’s more. The fairy godmother in the tale we know was more of an adviser to the prince in the opera. In the play, she has morphed into an Indian guru named Alidora.

“Little by little there’s a whole sort of Eastern, Indian feel that has come in. We’ve been deliberating what kind of slipper [Cindy Bella] is going to get. . . . We’re heading maybe towards twinkly Indian slippers. Slowly we’re going quite Bollywood,’’ Brook says.

It is still safe, however, to expect a happy ending.